The art is aware of the utilization of roll-over protective structures which are mounted on tractors to protect the operator in the event that the tractor rolls over. The structure is in the nature of a canopy extending over the operator's head, and it is available for protecting against any force applied toward the operator while he is seated on the tractor. It is common practice and significant that the protective structures are mounted on the tractor by the interposition of elastomer members which are interposed between the tractor chassis and the protective structure itself. As such, the elastomer members absorb or dampen vibration encountered in normal use of the tractor, and they are also available for absorbing shock when the protective aspect of the structure is being utilized. Of course it will be further understood that tractors are subjected to considerable shock and vibration, and thus the manner in which the protective structure is attached to the tractor is significant and is also important. That is, it must be shock and vibration resistant, it must be sturdy, it must be readily and easily assembled and disassembled, and it must have like and other characteristics.
With further regard to the prior art and the recognized concerns and problems in assembling the protective structures on the tractor, it is recognized and understood that the structure is assembled with a preload in the mount itself, that is, the elastomer member is actually under compression, in order to achieve the desired results, such as those mentioned above. To accomplish this, the prior art has resorted to different methods of achieving the assembly, such as forcing the parts into alignment for the purpose of making the assembly, and such forcing generally requires considerable effort and special attention is required in order to achieve the aligned and forced assembly for the final arrangement of the attachment to the tractor.
Accordingly, it is an object of this invention to provide a protective structure which can be readily and easily attached to a tractor but which has a desired amount of preload or compression in the elastomer member itself so that the desired and adequate assembly of the roll-over structure to the tractor is achieved. One example of a prior art arrangement is found in U.S. Pat. No. 3,851,982, and in that instance, some of the aforementioned problems of the prior art are recognized, and the resilient mount is preloaded in the assembled position. However, in that example, the assembly is arranged so that the mounting bolt itself is subjected to sheer or bending forces, since the forces acting on the bolt are at the center and at opposite ends and are transverse to the axis of the bolt, and the various parts employed in the assembly are arranged so that several of the metal parts are in direct contact or at least adjacent each other in the final assembled position. That is, the present invention provides an assembly wherein the full advantage and characteristic of an elastomer member is utilized in an interposed position between the tractor chassis and the roll-over structure or the post thereof.
Still further, it is an object and advantage of the present invention to provide a roll-over protective structure assembly which can be readily and easily achieved in the assembly of the parts and elements involved, and the tightening bolt, for instance can be easily placed into its position and the entire assembly can then be tightened. Further, it is the tightening feature itself which creates the preload on the elastomer member, and, until the tightening is initiated, the parts are freely aligned and easily assembled and only the tightening of the bolt is required in order to finalize the position of the parts and to create the preload desired. Further, the elastomer portion of the assembly is of sufficient and substantial stock to provide the necessary preload and cushion mount desired, and the elastomer member provides the cushion mounting in all directions radial of the axis of the assembly which is the longitudinal axis of the bolt itself.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.